Re: ultimate goal of DESTDIR support?

at the moment the default mode of installation pkgsrc supports is the
"traditional" one: install files into live system as user "root" and create
package from there.
Late in 2006 Joerg Sonnenberger added support for installation to a
directory DESTDIR: copy files as non-root user to temporary directory
DESTDIR, create binary package from those files and use pkg_add to add the
package to the live system.
Although I do not remember seeing this explicitly said anywhere, I always
had the impression that the intent of DESTDIR support was to get away
from the current (traditional) method, ie some day in the future pkgsrc
would use DESTDIR installations by default.
Is this impression correct? Or is "DESTDIR" installation just a
nice-to-have feature and takes second place in importance to the
traditional method?

Your impression is correct, although I don't believe the pkgsrc-pmc has
made any formal announcement of this fact. Purely from a technical
standpoint, it is much nicer to have a single way to install packages --
the DESTDIR approach is to only use binary packages -- instead of the
parallel methods currently used by the "traditional" method that depend
on whether you are building from /usr/pkgsrc or if you are installing
from a binary package.